Handset key matrix



FIG. 1 is a front elevational view of a handset key matrix showing our new design;

FIG. 2 is a front, right side and bottom perspective view thereof; and,

FIG. 3 is a front, left side and top perspective view thereof.

The evenly dashed lines around the key matrix indicate, but are not included in, the boundaries of the claimed design. The unevenly dashed lines showing a handset are for illustrative purposes only and form no part of the claimed design. 

The ornamental design of a "handset key matrix," as shown and described. 